#S(der0 li (b1 b2 g) gx gx gy dgy x dx y dy z dz)
dgs0
gs1-b1
#S(der1 x b3x gx b3gx li (b1 b2 g) gy gy y b2y)
gs0
gs1-b1
(meth base3 b3m0)
(meth der1 b3m1)
m1
m2
gm
m1
m2
gm
base1
base2
grand
(b1 b2 g)
(gf b2f b1f b1 b2 g)
(b1 b2 g)
(gf b2f b1f b1 b2 g)
(b1 b2 g)
(gf b2f b1f b1 b2 g)
(b2 b1 g)
(gf b1f b2f b2 b1 g)